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AIM: To observe the effect of intraocular lens ( IOL) implantation on visual acuity and contrast sensitivity in patients with cataract. METHODS: Fifty - eight cases ( 72 eyes ) cataract patients with regular cornel astigmatism, in our hospital from May 2014 to May 2015 were randomly divided into two groups to undergo phacoemulsification and IOL implantation: the observation group: 29 cases (36 eyes) received multifocal toric IOL implantation; the control group: 29 cases (36 eyes) received monofocal toric IOL implantation. Uncorrected distance visual acuity ( UCDVA), uncorrected near visual acuity ( UCNVA), best corrected distance visual acuity (BCDVA), the best corrected near visual acuity ( BCNVA ), total eye astigmatism, and the dark contrast sensitivity were observed for these patients at 1 and 6mo after cataract surgery. RESULTS: There were no statistical significant difference between the two groups at postoperative 1, 6mo on UCDVA, BCNVA, BCDVA and total eye astigmatism(P>0. 05). UCNVA of observation group at 1 and 6mo were better than those of control group ( P CONCLUSION: Both monofocal toric IOL implantation, and aspheric multifocal toric IOL implantation for cataract with regular corneal astigmatism are effective to improve visual acuity. But the latter treatment would contribute to the improvement of uncorrected near visual acuity and the dark contrast sensitivity.
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Background The mechanism of both selenite-induced cataract and age-related cataract is oxidative damage.N-acetylcysteine (NAC) is one of the effective antioxidants,but the literature is little about the preventive and treating effects of NAC on cataract. Objective This study attempted to investigate the preventive and therapeutical effects of NAC on the selenite-induced cataract,and to discuss the possible mechanism. Methods Sixty 10-day-old clean SD rats were randomly divided into normal control group-1,normal control group-2,selenite-induced cataract group,NAC preventive group,NAC+normal saline group and NAC treatment group.Selenite cataract models were induced by subcutaneous injection of 3.46 mg/kg sodium selenite once daily for three days.The rats of NAC preventive group received the intraperitoneal injection of 2 mmol/L NAC 30 minutes before the injection of sodium selenite once daily for 6 days.In NAC treating group,2 mmol/L NAC was intraperitoneally injected 1 day after the injection of sodium selenite for 30 days,and the normal saline solution was injected at the same method in the NAC+normal saline group.Lens opacification was graded according to LOCS Ⅲ criteria.Histopathological change of lens epithelium was examined under a light microscope after hemotoxylin and eosin staining,and the ultrastructure was observed under the scanning electron microscope.The expression of caspase-3 in lens was assayed using immunochemistry.The levels of superoxide dismutase ( SOD ),malonaldehyde ( MDA ) in rat lens were detected respectively in corresponding time points.The use of the experimental animals complied with the Regulation for the Administration of Affairs Concerning Experimental Animals by State Science and Technology Committee. Results In 7 days after experiment,lenses were completely clear in the normal control group.Lens opacification of Ⅴ grade was found in 11 eyes in selenite cataract model group,but no lens opacification of Ⅴ grade was seen in NAC preventive group,showing a significant difference(x2 =40.000,P＜0.05 ).In 30 days after experiment,Ⅳ- Ⅴ grades of cataracts were found in 20 eyes both in NAC + normal saline group and NAC treating group (x2=0.153,P＞ 0.05 ).Histopathological examination showed that lens structure was normal,and the separation between LECs and anterior capsule,the rupture of cellular membrane,deformation of cellular nuclei and the feature of lens fiber were seen in selenite cataract group,but the damage of lens was mild in the NAC preventive group.Ultrastructure of lens was obviously abnormal in selenite cataract group,NAC+normal saline group and NAC treating group.Expressions of caspase-3 and SOD in lens were significantly lower,but that of MDA was significantly higher in the selenite cataract group than the normal control group (P＜0.05) ;while those of the NAC preventive group were significantly different from selenite cataract group(P＜0.05).No significant difference was found in the expressions of caspase-3 and the levels of SOD and MDA between NAC+normal saline group and NAC treating group (P＞0.05 ). Conclusions Selenite can induce the apoptosis of LECs.NAC can evidently postpone formation of selenite cataract by increasing the activity of SOD,decreasing the level of MDA and the expression of caspase-3.However,NAC could not reverse selenite-induced lens damage.
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Background Implantation of phakic posterior chamber intraocular corrective lens(ICL)is a new choice for correction of high myopia.Different from laser assisted in situ keratomileusis,implantation of phakic posterior chamber ICL will allow the good imaging quality because it remaines the matched relationship between cornea and lens.But its visual quality after operation is concerned by patient and ophthalmologists.ObjectiveThis study was to observe the effectiveness of implantation of posterior chamber phakic ICL on visual quality in patients with high myopia.Methods Eighty-four high myopia eyes of 42 patients accepted implantation of posterior chamber phakic ICL and follow-up of 6-month duration.The visual acuity,refractive status,wavefront,contrast sensitivity and accommodation were examined and compared before and after surgery.This clinical study complied with Declaration of Helsinki.The written informed consent was obtained from each patient before operation.Results A prospective observational trial design was used.The uncorrected visual acuity and best corrected visual acuity after operation were better than preoperative ones in all of the patients.The eye numbers of ＞ 0.3 were increased after operation in comparison with before operation with a stable result among 1 day,1 month and 6 months after surgery (x2 =10.70,P＞0.05).Spherical equivalent refraction was(-15.38 ± 1.03)D before surgery and(+0.55 ±0.06)at 1 day,(-1.22±0.09)D at 1 month and(-0.68 ± 0.06)D after 6 months,showing a significant difference among them(F=16 559.90,P＜0.05).Total aberrations and higher-order aberrations were 11.00±0.25 and 0.43 ±0.05 before surgery,the wavefront aberrations were 2.21 ± 0.56 and 0.47±0.04 at 6 months after surgery with significant difference(t =1.65,P =0.10).Each spatial frequency contrast sensitivity and glare sensitivity on photopic and seotopie conditions in postoperation were higher compared with the preoperative(P＜0.05).The accommodation in 1 month and 6 months after surgery was greater than that of preoperative in the patients ＜-16 D(preoperation:2.75 ± 1.20 ; postoperation 1 month:5.75 ± 1.44,postoperation 6 months:6.00 ± 1.52)(P＜ 0.05),however,in the ＞-16 D group,no considerably change in accommodation was seen after surgery(F=1597.70,P＜0.05).No significant difference was found in accommodation between before and after surgery in ＞-16 D group(F=2.67,P＞0.05).Conclusions Visual quality of high myopia is obviously improved after implantation of posterior chamber phakic ICL,but its long-term outcome is need to further study.
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Background High myopia can be corrected using laser therapy and intraocular lens(IOL)implantation.IOL implantation is more suitable than laser therapy for high myopia if the patients suffer from thinner cornea.Objective This clinical trail was to assess and compare the visual quality following phakic iris-claw intraocular lens (IOL) and implantable contact lens(ICL) implantation for high myopia.MethodsIris-claw phakic intraocular lens was implanted in 17 eyes of 10 patients with high myopia,and age-,refractive-matched 17 eyes of 9 patients were in implantable contact lens (ICL) implantation group.Uncorrected visual acuity,best correct visual acuity,contrast sensitivity under the 3,6,12 and 18 c/d spatial frequencies,wave-front aberrations,including RMS3,RMS4 and RMSh,were examined in 6 months after operation.Written informed consent was obtained from each patient before surgery.Results There were no significant difference in uncorrected visual acuity,best correct visual acuity between two groups(t=0.489,P>0.05;t=0.853,P>0.05).Non-glare CS under the 3 c/d,6 c/d,12 c/d and 18 c/d spatial frequencies were insignificantly different between two groups ( t = 0. 906, P > 0.05 ; t = 0. 103, P > 0. 05 ; t =0. 694 ,P>0. 05 ; t = 1. 583, P>0. 05), and the similar outcomes were found in glare CS ( t = 0. 323, P>0.05, t =0.041 ,P>0. 05, t = 0.024, P>0. 05; t = 0. 363, P>0.05) in postoperative 6 months. RMS3 and RMSh were significantly elevated in PIOL group compared with ICL group ( t = 11.40, P0. 05). Conclusion Both PIOL and ICL implantation for high myopia can achieve an equal visual acuity. But clinical outcomes of ICL implantation is much better than PIOL group. A long-term effect should be observed for the further evaluation.
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<p><b>BACKGROUND</b>Astigmatism is one of the most significant obstacles for achieving satisfactory visual function. This study was to evaluate the influence of astigmatism on contrast sensitivity (CS) and higher-order aberrations.</p><p><b>METHODS</b>CS, accommodation response and wavefront aberration were measured in 113 patients with astigmatism, aged 18 - 36 years. Both single and binocular visual performance were examined under four lighting conditions: photopia, photopia with glare, scotopia and scotopia with glare respectively. Accommodation response was classified as normal, abnormal and low. The contribution of the power and axis of astigmatism to CS, accommodation response and wavefront aberration was analyzed.</p><p><b>RESULTS</b>As the dioptric power of astigmatism increased, the loss of CS spatial frequency changed from high to intermediate, and then to low frequency. CS scores varied at different illuminance levels, descending in the following sequence: photopia, photopia with glare, scotopia, and scotopia with glare. However, the normal accommodation group showed better CS values under photopia with glare than without glare. The range of influenced direction of sine-wave gratings remained mostly at the meridian line of high dioptric power, which would be expanded when optical accommadation attenuated. The patients with symmetrical astigmatism got higher CS scores with binoculus vision than with dominant eye vision, while the patients with asymmetrical astigmatism did this only at scotopia with glare. Among higher-order aberrations, coma aberration, secondary coma aberration and the total higher order aberration were influenced by astigmatism, all of which rising with the power of astigmatism increased.</p><p><b>CONCLUSIONS</b>Reducing astigmatism might improve the performance of visual function. Not only the power of astigmatism should be cut down, but also the binocular axes should be made symmetrically.</p>
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Adolescent , Adult , Female , Humans , Male , Astigmatism , Contrast Sensitivity , Vision, OcularABSTRACT
<p><b>BACKGROUND</b>Caspases are important in the signaling pathway of cellular apoptosis. Caspase-3 protein expression has been shown to increase and parallel to neuronal apoptosis in retinal ischemia injury. This study was to determine whether caspase-1 is involved in neuronal cell death or in retinal ischemia and reperfusion injury.</p><p><b>METHODS</b>In twenty-one adult mice, ischemia was induced by increasing the intraocular pressure. The animals were sacrificed at 1 hour, 3 hours, 6 hours, 1 day, 3 days and 7 days after reperfusion. Frozen sections were used for caspase-1 immunostaining and TUNEL labeling.</p><p><b>RESULTS</b>In normal retina, no caspase-1 positive cells were seen. One hour after ischemia, numerous positive cells were noted in the ganglion cell layer (GCL) and inner side of inner nuclear layer (INL). At 3 hours, caspase-1 positive cells continued to increase and peaked at 6 hours, then decreased significantly at 1 day. TUNEL positive cells were detected at 3 hours and peaked at 1 day after ischemia. Double labeling of caspase-1 and TUNEL only showed few cells with co-localization after ischemia.</p><p><b>CONCLUSION</b>Caspase-1 immunoreactivity preceds to the TUNEL labeling in the GCL and INL after retinal ischemia and reperfusion injury and its early activation may play an important role in the initiation of neuronal apoptosis.</p>